The invention relates to a marker assembly for use with a microscope which may be used to mark a particular area of a specimen which is placed under the microscope.
In the observation of specimens under the microscope, it is essential that a particular area of the specimen be marked in order to permit a subsequent repeated observation or more close examination, in particular when a number of specimens are observed in succession. The marking of specimens frequently takes place during the actual examination.
A selected area of the specimen can be marked by handwritten marking with a pen or by using a marker. A handwriting is enabled only when the objective lens of the microscope has an increased distance corresponding to a magnification of 10X or 20X, for example. Further, a handwritten marking requires a skill on the part of the user in order to achieve a desired accuracy. Still, a skilled operator may suffer from a failure or inaccuracy, and in any event requires an increased length of time to complete the marking. These disadvantages can be overcome by employing a marker assembly, one example of which is illustrated in FIG. 1.
Referring to FIG. 1, there is shown a marker 1 which is generally similar in configuration to an objective lens barrel of a microscope. It includes a barrel 4 having no objective lens disposed therein, and a marking member 5 which is mounted around the barrel 4 so as to be vertically movable. The top end of the barrel 4 is peripherally threaded as shown at 2 which may be engaged by a knob 3 for connection with a revolver mechanism of the microscope in juxtaposition with an adjacent objective lens. The lower end of the barrel 4 is formed with a flange 4a and the marking member 5 is fitted around barrel 4 from below.
The marking member 5 comprises a hollow cylindrical body which is open in its top and which is provided with a bottom, which is centrally formed with a ring-shaped, downwardly depending marking piece 5c. The top end of the marking member 5 is peripherally formed with threads 5a, which are engaged by a sleeve-shaped knob 6 having an open bottom. A coiled tension spring 8 is disposed around the barrel 4 in the space between the barrel 4 and marking member 5, and abuts against the top surface of the knob 6 and the flange 4a, thus normally urging the marking member 5 upward. The resulting movement is usually blocked by the abutment of a step 5b which is formed on the lower inner surface of the marking member 5 against the flange 4a.
In use, the marker 1 is initially mounted on the revolver in juxtaposition with an objective lens of the microscope. The objective lens is located directly above a specimen 7, and while viewing the eyepiece of the microscope to observe the specimen 7, a focussing and/or movement of the specimen 7 is performed until a desired area of the specimen 7 is located within the field of view. Then the revolver is turned to locate the marker 1 directly above the specimen 7, and the marking member 5 is moved down by manually operating the knob 6, whereupon the marking piece 5c which is previously inked is brought in abutment against the specimen 7 to mark a desired area thereon. When the knob 6 is then released, the resilience of spring 8 returns the marking member 5 to the position shown in FIG. 1, removing the marking piece 5c away from the specimen 7. If required, the revolver may be turned again to locate the objective lens directly above the specimen 7 in order to confirm the mark which is put on the specimen 7.
It will be noted that the objective lens will be closely spaced from the specimen 7 when it is focussed. Also, the marker is not always identical in size and configuration with the objective lens. These factors may cause the specimen 7 to be inadvertently moved by the objective lens or the marker 1 when turning the revolver in order to shift from the objective to the marker, thus causing the desired area of the specimen 7 to be moved out of view. Another disadvantage of the described arrangement is the fact that it requires a number of operational steps, including recognizing a desired area of the specimen 7 in the field of view of the objective lens, turning the revolver to locate the marker 1 directly above the specimen 7 and manually depressing the knob 6. If it is desired to confirm the mark which is put to the specimen 7, the revolver must be turned again to locate the objective lens directly above the specimen 7.
The marking member 5 is usually formed of a metal material, and hence it is necessary to ink the marking piece 5c with a brush prior to the marking operation. Such necessity represents a further drawback in the ease of operating the marker. In addition, the form of a mark put to the specimen is limited to a ring form which is aligned with the optical axis of the objective lens, and it has been impossible to choose other form of the marks freely.